Psychopathology, Psychosocial Problems and Substance Use During Pregnancy: screening and referral towards care

__Abstract__ The overall aim of the present thesis is to demonstrate the feasibility of an innovative screenand- advice instrument, for routine screening and subsequent referral to tailored care of pregnant women with psychopathology, psychosocial problems and substance use. Firstly, this dissertation addresses how and by whom PPS risk management should be performed, with regard to screening and subsequent guidance to specialised care, if indicated. Secondly, this dissertation outlines recommendations for a targeted prevention of poor perinatal health related to PPS, by investigating the role of PPS in the pathway to the preterm birth, birth weight and small for gestational age. To that purpose fi ve research questions are answered: 1. What is the prevalence of psychopathology, psychosocial problems and substance use during pregnancy in a large Dutch urban area? (chapter 2) 2. Is the Mind2Care screen-and-advice instrument a reliable and valid instrument for routine use in obstetric care? (chapters 2, 3, and 4) 3. Is the antenatal screening for depressive and/or anxiety symptoms biased by worries surrounding the fi rst ultrasound examination? (chapter 5) 4. How many pregnant women identifi ed as being at risk for PPS after screening eventually receive specialized treatment? (chapter 6) 5. What is the role of psychopathology, psychosocial problems and substance use in the pathway to adverse pregnancy outcomes? (chapters 7 and 8)

Complexity and integrability in 4D bi-rational maps with two invariants

In this letter we give fourth-order autonomous recurrence relations with two invariants, whose degree growth is cubic or exponential. These examples contradict the common belief that maps with sufficiently many invariants can have at most quadratic growth. Cubic growth may reflect the existence of non-elliptic fibrations of invariants, whereas we conjecture that the exponentially growing cases lack the necessary conditions for the applicability of the discrete Liouville theorem.Comment: 16 pages, 2 figure

Construction of Integrals of Higher-Order Mappings

We find that certain higher-order mappings arise as reductions of the integrable discrete A-type KP (AKP) and B-type KP (BKP) equations. We find conservation laws for the AKP and BKP equations, then we use these conservation laws to derive integrals of the associated reduced maps.Comment: appear to Journal of the Physical Society of Japa

Using discrete Darboux polynomials to detect and determine preserved measures and integrals of rational maps

In this Letter we propose a systematic approach for detecting and calculating preserved measures and integrals of a rational map. The approach is based on the use of cofactors and Discrete Darboux Polynomials and relies on the use of symbolic algebra tools. Given sufficient computing power, all rational preserved integrals can be found. We show, in two examples, how to use this method to detect and determine preserved measures and integrals of the considered rational maps.Comment: 8 pages, 1 Figur

Comment on `conservative discretizations of the Kepler motion'

We show that the exact integrator for the classical Kepler motion, recently found by Kozlov ({\it J. Phys. A: Math. Theor.\} {\bf 40} (2007) 4529-4539), can be derived in a simple natural way (using well known exact discretization of the harmonic oscillator). We also turn attention on important earlier references, where the exact discretization of the 4-dimensional isotropic harmonic oscillator has been applied to the perturbed Kepler problem.Comment: 6 page

A Characterization of Discrete Time Soliton Equations

We propose a method to characterize discrete time evolution equations, which generalize discrete time soliton equations, including the $q$-difference Painlev\'e IV equations discussed recently by Kajiwara, Noumi and Yamada.Comment: 13 page

Singularity, complexity, and quasi--integrability of rational mappings

We investigate global properties of the mappings entering the description of symmetries of integrable spin and vertex models, by exploiting their nature of birational transformations of projective spaces. We give an algorithmic analysis of the structure of invariants of such mappings. We discuss some characteristic conditions for their (quasi)--integrability, and in particular its links with their singularities (in the 2--plane). Finally, we describe some of their properties {\it qua\/} dynamical systems, making contact with Arnol'd's notion of complexity, and exemplify remarkable behaviours.Comment: Latex file. 17 pages. To appear in CM